Installation instructions are for F Gas registered firms and engineers only. All Qualitair cellar cooling systems are pre-programmed to maintain a cellar temperature of 12C (Plug & Play) the electronic control can be adjusted down to 1C providing the room is sized with the system, Standard systems only, Slimline systems cannot operate below 11C. The QP35CU and QP50CU outdoor condensing units are for both QP35/QSL35 and QP50/QSL50 Standard and Slimline indoor units. All units are R32 gas. Qualitair offer technical advice by phone or email.